fix: data is not appended with committed streams

[tomrussello]

With the Big Query Storage API, when using a committed stream, I had the same issue as #247. Looking at the code, it seems that no commit was done to the transaction

[totem3]

Thank you for your pull request.
We would like to have automated tests to verify that this fix actually solves the issue.
I have written a test for this PR here (tomrussello#1).

@goccy, I have confirmed with the above test that this Pull Request actually fixes the issue.
It has been verified that data in Pending Streams does not become valid until the stream is Finalized and Committed, and in Committed Streams, the data becomes valid automatically with each write.

If possible, I would appreciate it if you could review the PR (including tests in tomrussello#1).
If it's better to bundle the test and this fix together into a single Pull Request for this repository, please let me know.

[tomrussello]

Thank you @totem3 for adding the testing part and confirming the fix.

Waiting for @goccy's input before merging anything in my branch

[goccy]

@totem3 OK, Thank you for testing this.
@tomrussello Please let me know when the test code is added and I will merge this.

[tomrussello]

@goccy code is added to my branch

[goccy]

Thank you for your contribution !! LGTM 👍

[tomrussello]

@goccy Do you know when a new release will be created, please?